Means for and method of handling work pieces



Aug. 4, 1925,] 1,548,562

H. K. I SPENCER mms FOR AND METHOD OF HANDLING wonx PIECES Filed May 16 Q 1921 s Sheets-:Sheefi 1 1,548,562 H. K. SPENCER MEANS FOR AND METHOD OF HANDLING WORK PIECES Filed May 16'. 1921 3 sheets sheet 2 I liv/venior: HnifyESpemen Aug. 4, 1925.

H. K. SPENCER MEANS FOR AND METHOD OF HANDLING WORK PIECES Filed May l6 i921 5 sheets sheet 5 5 I nae-715702 flenrylflspemoen Patented Aug. 4, 1925.

UNITED s-rares PATENT OFFICE.

HENRY K. SPENCER, F WATERTOWN. MASSACHUSETTS, ASSIGNOR TO THE BLAN- CHAIBID MACHINE COMPANY, OF CAMBRIDGE, MASSACHUSETTS, A CORPORATTON OF MASSACHUSETTS.

MEANS FOR AND METHOD OF HANDLING WORK PIECES.

Application filed May 16, 1921.

To all whom it may concern:

Be it known that I, HENRY K. SPENCER, a citizen of the United States, and a resident of VWatertown, in the county of Middlesex and State of Massachusetts, have invented an Improvement in Means for and Methods of Handling Vork Pieces, of which the following description, in connect-ion with the accompanying drawings, is a specification,

like parts.

This inveiition relates to magnetic hold ing means and methods of handling work pieces, and aims to provide a method of, and means for, facilitating the handling of a succession of pieces which are magnetically held while work is being performed oning means, and by which the method of handling magnetic work piecesmay be carried into effect;

Fig. 2 is a sectional view on an enlarged scale on line 22 of Fig. 1;

Fig. 8 is a sectional view on line 33 of Fig. 2, but at a reduced scale;

Fig. i is a detail sectional view on line .4.4 of Fig. 1: and

Fig. 5 is a diagrammatic view illustrating the wiring.

Referring to the drawings, and'to the embodiment of the invention which is selected for exemplification, there is shown a portion of a metal working tool, specifically a vertical surface grinder whose general features are similar to that which is the subject matter of United States Letters Patent No. 1,182,861, issued May 9, 1916, to which reference may be had for details not like characters on the drawings representing Serial No. 470,192.

disclosed herein. The machine is provided with an annular grinding wheel 8 (Fig. 1), mounted on a vertical spindle 10 carried by a wheel head 12 which is mounted to travel vertically on a column 14. In the operation of the machine, the wheel is rotated in the direction of the arrow thereon.

The base of the machine (not herein shown) supports a working table comprising a table body 16 2), which presents an annular bearing 18 for a ring gear 20 of non-magnetic material, the latter being driven by a suitable mechanism including a pinion (not shown). This gear constitutes aoarrier for a chuck ring 22, also of nonmagnetic material, and chuck body 24 of magnetic material suitably-secured thereto as by screws 26, one of which is shown at the left-hand side of Fig. 2. The chuck body is held properly centered by a chuck center or spindle 28, also of non-magnetic material appropriately secured thereto as by a nut 3O, likewise formed of non-magnetic material threaded onto the chuck center.

' The latter has a depending portion 32,

which turns in a bearing 34 provided in the table body 16. In the operation of themachine, the pinion rotates the gear, and the latter turns the chuck body about a vertical axis, thereby carrying beneath the grinding wheel work pieces supported on the face of the chuck body.

In the machine of the aforesaid patent, the work-holding means is a magnetic chuck on which work pieces are held magnetically, while they are being presented to the action of the grinding wheel. In the operation of said machine as heretofore used, for small pieces, the latter are simply laid on the chuck all at one time, the machine is started into operation, the grinding of the pieces takes place, and when it is completed, the machine is stopped and the pieces are removed from the chuck at one operation. This mode of operation is satisfactory for work which requires to be brought under the grinding wheel several times before the grinding operation is completed, and the work brought to the proper size. There is another class of work, however, which requires but a single pass beneath the grinding wheel, and this is the class to which my present invention is directed.

The chuck body 24 presents an annular chamber.36 forone or more, herein a series of, magnets 38 having windings 40 wound in the same direction connected to eachother in series and receiving current from a suitable source 42, the terminals of which are connected to the coils by lead-wires 44 and 46. The area of the chuck face served by these magnets is less .than the .total area, and herein a zone of substantially 180 degrees. In order to confine the magneticflux to this zone, the chuck body is suitably slotted and grooved. In the present example, :the face of the chuck body is provided with radial grooves 48, which may be filled with non-magnetic strips to exclude foreign matter therefrom. The face may be further provided with vannular grooves 52 filled with DOHflHSJg-DEl lC rings .for a like purpose. These annulargrooves divide the face of the chuck body into a multi- ;plicity ofismallipolepieces, after the-manner .of thechuck which "forms the subject matter of United States Letters Patent No. 1,125,198, issued to me January 19, 1915. The radial grooves ,intersect the annular ones, and are preferably shallower than the wlatter. Itifollo-ws that the annular strips are notched to :receive the :radial strips (see 'Fig. The chuck body is further provided with two sets of radial. slots 56 and 58, to assistiu'the localization of the magnetic -;zone, and :to strengthen the chuck body where it is so cutaway, SIhave herein proivided inner and outernon-magnetic'rings G0 and '62, received in grooves '64 and 66, respectively, provided in the chuck :body Fi 4) 1 mile the chuck body is mounted :to ro- .tate,-the magnets in the present example are fixed. Theyare conveniently supported on a znon-magneticwring 68, to which they are suitably secured as by screws andWQI, while the ring in turn is secured to the table body 16 as by screws 74.

It will be evident from an inspection of Fig. 4; that there :is comparatively little of the chuck body which presents a continuous annular connection between the segments formedby the described radial grooves and .;slot;s, so little, in fact, that the magnetic leakage from one to =the other is very slight. -It i-s therefore apparent that the influence of the magnets will extend practically to only the chuck body segments with which they are associated. In other words, vthe imagneticzone is confined-to the area'which is adjacent to the magnets. .When. there-- fore, the chuck body is rotated and magmesses netic work pieces are placed thereon, within the non-magnetic zone represented in Fig. 1., they may be moved about freely by the hand of the operative and properly positioned for the action of the grinding wheel. Rotation of the chuck brings a procession of the work pieces successively into the magnetic zone represented in Fig. l, and .the pieces are immediately magnetized and thus held in place on the chuck face. During the grindingoperation, the pieces pass beneath and then beyond the grinding wheel and out of the magnetic zone into the non-magnetic zone, where they are released and can '78 suitably connected in circuit with the source of current 42, there being provided a rheostat in scries withythe magnet for the purpose of varying the effectiveness of the latter. This is found desirable in practice, large and small, and hard and soft, pieces of work differ in the extent to which they become magnetized. and the corresponding strength required of the releasing magnet to demagnetize or release them. I prefer to provide in addition to :the rheostat 80 a resistance coil 82 in series with the rheostat and releasing magnet, as the use ofthis resistance permits the cm ployinent of a rheostat smaller in size than would otherwise be necessary.

The releasing magnet is inountedou the ring 68 in a manner similar to the mounting of the holding magnets, except that it is preferably adjusted in a circumferential direction, and to that end, the ring is herein provided with segmental slots 84', 86, which receive clamping crews 88 and 90. respectively (right-hand side of Fig. 9.) threaded v into the magnet. screws are loosened, the magnet may be lVhen, therefore, these moved to and fro to an extent limited by ,the length of the slots, and when the position is reached where the magnet is most 'eifective for the particular class of work,

the magnet is secured in place by tightening-the screws. 7 ternuned, it will usuallybc unnecessary to readjust the magnet from time to time as its effectiveness can be controlled to a -nicety by the use of the rheostat.

hen this position is do Having thus pecifically described the con- .struction and mode of operation of the chuck,

I will describe the method ofhandling the work pieces.

92 on the chuck face. Assuming the direction of rotation of the chuck to be as This 'is well illustrated in Fig. 1, wluchshows a number of work pieces the operative places the pieces in succession in one or more row upon the chuck face, while the latter is being rotated. The nonmagnetic zone should be of sullicient area to give the operative time to position the pieces properly for the grinding operation, and to remove the finished work. Rotation of the chuck causes the pieces to pass into the magnetic field, whereby they are held in place during the performance of the work. After the latter has been completed, continued rotation of the chuck carries the pieces out of the field of the holding magnets 38 into the field of the releasing magnets 76, which causes: the prompt release of the piecesand permits them to be removed from the chuck face.

Having thus described one embodiment of my invention, but without limiting myself thereto, what I claim and desire by Letters Patentto secure is:

1. The method of handling work pieces which comprises placing the pieces in succession upon a suitable movable support,

causing the pieces while on the support to pass into a magnetic field and to be held magnetically on the support, performing work on the pieces so held, and causing the pieces, while on the support, to pass out of the magnetic field.

2. The method of handling work pieces which comprises placing the pieces in a row upon a suitable movable work support, causing the pieces, while on the support, to pass in a procession into a magnetic field and to be held magnetically on the support, performing work on the pieces so held, and causing the pieces, while on the support, to pass in a procession out of the magnetic field.

3. The method of handling work pieces which is characterized by carrying the pieces on a work support into and out of a magnetic zone, magnetically holding the pieces on said support while in'said zone, and performing work on said pieces while in'said zone.

4. The method of handling work pieces which is characterized-by placing the work pieces on a work support while in a nonmagnetic zo-ne, carrying the pieces, while on the support, into a magnetic zone to cause thepieces to be held on the support, performing work on the pieces while so held, and carrying the pieces from the magnetic zone into anon-magnetic zone.

5. The methodof handling work pieces which comprises placing'the pieces on a suitable work support, causing the pieces, while on the support, to pass in a procession in ,a magnetic zone, magnetically holding the pieces on said support while in said zone, performing work on the pieces successively while in the magnetic zone, carrying the pieces from the magnetic zone into a non-magnetic zone, and removing the pieces from the work support after passing from said magnet1c zone.

6. In a magnetic holding device, the

combination of a movable work support, and electro-magnetic means for producing a local magnetic field to hold the work on said support, said means having provision to cause the work to be held when said work support is in one position and to be released when said work support is in another position.

7. In amagnetic holding device, the combination of a travelling work support, and means for producing a magnetic field effective at a part only of said work support, and to cause said field to remain fixed relatively to the travel of said work support.

8. In a magnetic holding device, the combination of a travelling work support a part of which has an orbital path, and means for producing a magnetic field effective at a part only of said path, and to cause said field to remain fixed relatively to the travel of said work support.

9. In a magnetic holding device, the combination of means for producing a magnetic field, and means includinga travelling work support for carrying magnetic work-pieces into and out of said field.

10. In a machine of the class described, the combination of means for producing amagnetic field, means including a travelling work support for carrying magnetic work pieces into and out of said field, and means for performing work on said pieces while they are in said field.

11. In a machine of the class described, the combination of means for producing two magnetic fields, one of which attracts and the other demagnetizes magnetic objects, and means including a travelling work support for carrying magnetic objects from one of said fields to the other.

12. In a machine of the class described, the combination of means for producing two magnetic fields, one of which attracts and the other demagnetizes magnetic objects, and means including a travelling work support for carrying magnetic objects first into the field which attracts said objects and then into the field which repels said objects.

13. In a machine of the class described, the combination of means for producing two magnetic fields, one of which attracts and the other demagnetizes magnetic .objects, means including a travelling work support for carrying magnetic objects first into the field which attracts and then into the field which repels said objects, and means for performing work on said objects while they are in the first field.

14. In a magnetic holding device, the

. comprising,

combination of a travelling work support, and means for producing a magnetic zone which is relatively fixed with reference to the travel of said work support.

15. The combination of work performing means, a travelling work support which moves relatively to said means, and means for producing a magnetic zone within whose influence magnetic objects are held on said support and are operated on by said workperforming means and from which zone said objects are carried by said support after the performance of the work.

16. The combination of a work support, means for creating a magnetic zone which travels relatively to said work support, and means for performing work on magnetic objects while within said zone.

17. Electro-inagnetic means comprising, in combination, a series of'magnetic sectors, a series of electro-magnetsassociated there with and creating a magnetic zone, and means to cause said zone to travel from sector to sector.

18. An apparatus of the classdescribed comprising, in combination, a magnetic sector,- electro-magnetizing means associated with said sector and creating a magnetic zone, and a travelling work support a part of which is within said zone and a part without, the travel of said support causing different parts of said support to be presented within said zone.

19. An apparatus of the class described in combination, a magnetic sector, electr0magnetizing means associated with said sector and creating a magnetic zone, and a travelling magnetic work support a part of which is within said zone and a part without, the part'which is within, together with said sector, presenting a circuit for the magnetic flux, the travel of said support causing different parts of said support to be presented within said zone.

20. An apparatus of the class described comprising, in combination, a series of magnetizing coils, and a travelling magnetic work support associated therewith and presenting divisions crosswise ofthe travel of said support.

21. 'An apparatus of the class described comprising, in combination, a series of magnetizing coils, and a travelling magnetic work support associated therewith and presenting reduced cross-sectional areas crosswise of the travel of said support.

22. The combination of a; magnet having a coil through which current is passed in one direction, a magnet having a coil through which current is passed in the opposite direction, and means for. carrying HlEtgIlGtIQ work pieces first within the field of one magnet and then within the field of the other.

23. The combination of a magnet having a coil through which current is passed in one direction, a magnet having a coil through which current is passed in theoppo site direction, means for varying the eflec-' tiveness of one of said coils, and means "for carrying magnetic work pieces first within the field of one magnet and then within the field of the other. i

24. The combinationof a magnet having a coil through which current is passed in one direction, a magnet having a coil through which current is passed in the opposite direction, means for varying the strength of one of said fields, and means for carrying magnetic work pieces first within the field of one magnet and then within the field of the other.

25. The combination of a magnet having a coil through which current is passed in one direction, a magnet having a coil through which current is passed in the opposite direction, a variable resistance in circuit with one of said coils, and means for carrying magnetic work pieces first within the field of one magnet and then within the field of the other.

26. The combination of a magnet having a coil through which current is passed in one direction, a magnet havinga coil through which current is passed in the opposite direction, a variable and a non-variable resistance in series with one of said coils, and means for carrying magnetic work pieces first within the field of one magnet and then within the field of the other.

27. The combination of a moving work support, and means for producing different intensities and directions of magnetic flux within the space occupied by said work support, the flux having substantially no absolute motion.

28. The combination of a moving work support, and means for producing different intensities and directions of magnetic flux within the space occupiedby said work support, so that any portion of the work support, together with the adjacent work, passes through magnetic fields of varying intensities and directions.

7 29. The combination of means for producing a magnetic zone, and means for carrying magnetic objects into and out of said zone, the last mentioned means including a carrier upon which said objects rest by gravity while travelling through said zone.

30. The combination of means for producing a magnetic zone, andmeans for carrying magnetic objects into and out of said zone, the last-mentioned means comprising a magnetic carrier which is magnetized by the first-mentioned means and thus attracts said objects.

31. The combination of means for producing a magnetic zone, and means for carrying magnetic objects through said zone, the last-mentioned means comprlsmg a carrler having a generally horlzontal surface which supports said objects and causes them to travel in a generally horizontal direction.

32. The combination of means for producing a magnetic zone, means comprising a carrier for supporting magnetic objects and carrying them through said zone While so supported, and Work-performing means a 10 sociated with said zone for co-operation With said magnetic objects While the latter are passing through said Zone.

In testimony whereof, I have signed my name to this specification.

HENRY K. SPENCER. 

